I want to change two things: theme (I use Qt5CT and the font is black on black currently), and the controls (specifically, ctrl+scroll behavior).

I have checked all categories in the menu action bar, and looked at the tooltip of every button. I cannot find an action button named "Settings", "Preferences", or "Options".

It would be really funny if that's because I amlooking at black on black text. But still, developers, please put it in File>Settings or Window>Settings.